EPHD Research on Data Sources Used To Construct Environmental Quality Index Published in American Journal of Public Health

Although a strength of the environmental public health literature is its geographic breadth (ranging from national to local levels), one limitation is its restriction to single media--or even single contaminant--assessment, which fails to address the multiple environmental conditions to which people are exposed simultaneously. Environmental disamenities, such as landfills or industrial plants, often are located in neighborhoods with a high percentage of minority and/or poor residents, potentially contributing to adverse health outcomes and health disparities, while high-income neighborhoods are more likely to contain amenities conducive to promoting good health (e.g., parks, grocers). The differential distribution of disamenities results in the clustering of adverse exposures, and this environmental injustice has been well noted within the literature.

In an effort to learn more about how multiple environmental factors combine to contribute to adverse health outcomes and to better estimate the larger environmental and social context to which humans are continuously exposed, researchers at NHEERL’s Environmental Public Health Division are developing an environmental quality index (EQI) for all counties in the United States. Their recently published paper describes the quality and availability of the data used to construct the EQI based on five environmental domains: air, water, land, built environment, and sociodemographics. The paper was published as part of a special issue of American Journal of Public Health, which features commentaries, editorials, and research that were part of the U.S. EPA’s March 2010 symposium “Strengthening Environmental Justice Research and Decision Making: A Symposium on the Science of Disproportionate Environmental Health Impacts.”

The researchers found data sources to represent each of the five a priori identified domains: air domain (12 data sources identified, two retained), water domain (80 sources identified, nine retained), land domain (80 sources identified, six retained), built environment (12 sources identified, four retained), and sociodemographics (three sources identified, all retained). Each data source has been used previously in published literature and is reasonably well documented. Despite finding a considerable number of data sources to represent the environmental domains, significant data gaps exist, and this paper documents both the strengths and weaknesses of the data sources used.

The ability to estimate the full range of environmental exposures is critical for environmental justice, both to document and then address environmental health disparities. The researchers believe the process used to create the EQI, as well as the EQI tool itself, will be useful for investigators researching health disparities. The process described is easily replicable at various units of geographic aggregation, and the EQI tool will enable researchers interested in a given environmental exposure to control for the county-level environmental conditions with only one (EQI) variable. This paper describes the environmental quality data that are available at the county level across the United States. The majority of data sources identified here are available publically, which community leaders, advocates, and residents can explore for answers to environmental health questions.